This present disclosure relates generally to drilling operations. More specifically, the present disclosure relates to Horizontal Directional Drilling (HDD) techniques used in forming boreholes for the installation of infrastructure lines for utility, distribution, and transmission underground infrastructures.
Underground infrastructure lines may be installed between locations along surface or subsurface paths. Such underground infrastructure lines may include power, water, wastewater, fiber optics, gas, or petrochemical lines. The installation of underground infrastructure lines may encounter obstacles, such as roads, hills, structures, bodies of water, environmentally sensitive areas, etc. To circumvent such obstacles, the underground infrastructure lines may be installed by horizontally drilling subsurface paths between the locations and passing the underground infrastructure lines through such subsurface paths.
The subsurface paths are formed by drilling boreholes from a first location into subsurface formations and exiting at a second surface location a distance from the first location. In some cases, the boreholes extend a distance between locations below the surface to pass below the obstacles. For example, the boreholes may be drilled from the first location on one side of a river, pass below the river, and exit at the second location on another side of the river. The underground infrastructure lines are then passed through the borehole to commonly connect to infrastructure equipment on both sides of the river.
The borehole may be drilled using drilling equipment including a drilling rig for advancing a drilling tool through the subsurface formation. The drilling tool includes a drill string with a bit at a distal end thereof. This drilling equipment may directionally drill the borehole. Examples of drilling equipment are described in U.S. Pat. Nos. 7,942,609, 6,854,190, 4,319,648, 5,490,569, 5,209,605, and 4,221,503, the entire contents of which are hereby incorporated by reference herein.
Despite advances in underground infrastructure drilling, there remains a need to provide efficient and effective HDD techniques capable of operating in a variety of formations and/or preventing damage to the borehole and surrounding formation, such as drill mud frac-outs, collapse, dog-leg-severity, tortuosities, etc., that may occur during drilling. The present disclosure is directed at such needs.